OK; so can identical twins ever look different?
Err; yes! Even though I said above that identical twins are from the same sperm and egg; and therefore have exactly the same set of chromosomes and therefore genes; researchers are realising that there are other forces at play – the science of epigenetics. Epigenetics basically says that just because 2 people have the same set of genes (like identicals); because of the different environments the experience – i.e. in the womb (maybe one got more nutrients than the other); the types of illnesses they have had as they grew up; the lifestyle they lead etc etc; that there can actually be differences in how much each twins genes are turned on or off – this can then affect the way each twin looks and behaves. This effect actually increases as the identical twins get older – because more and more environmental events happen that are different between each twin – different friends; illnesses; jobs; partners; habits etc. There is another cause of differences in identicals which occurs in female
